Driving means for phonographs



H. K. SANDELL.

nmvms MEANS FOR PHONIOGRAPHS.

APPLICATION FILED APR-1.7, 1919- 1,416,306. Patented y 16, 1922.

3 SHEETSSHEET L' I l I H. K. SANDELL.

DRIVING MEANS FOR PHONOGRAPHS.

APPLICATION FILED APR-17,1919- 1,416,306. Patented May16, 1922.

3 SHEETS-SHEET Z.

H..K. SANDELL.

DRIVING MEANS FOR'PHONOGRA-PHS.

APPLICATION FILED APR. II. 191 9.

1,416,30 Pat nted May 1 6,1922.

3 SHEETS-SHEET 3.

UNITED STATES PATENT OFFICE.

HENRY K. SANDELL, Q1 CHICAGO, ILLINOIS, ASSIGNOR T HERBERT S. MIILS, OF CHICAGO, ILLINOIS Specification of Letters ratent.

Patented May 16, 1922.

Original application filed April 5, 1918, Serial No. 226,804. Divided and this application filed April 17,

' 1919. Serial No. 290,705.

To all whom it may concern:

Be it known that I, HENRY K. SANnELL, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Driving Means for Phonographs, of which the following is a specification. I

My invention vrelates to improvements n drivlng means for phonographs and W111 be fully understood from the following description taken in connection with the accompanying drawings in which Figure 1 is a bottom plan view of a phonograph table constructed in accordance with my 1nvention; Figure 2 is a transverse section on the line 2-2 of Figure 1. Figure 3 is a detail section of the governor taken on the line 3-3 of Figure 1. Figures 4: and 5 are add1- tional details of the governor taken, respectively, on the lines4-4 and 5-5 of Figure 1. Figure 6 is an enlarged plan v ew of a fragment of the motor. Figure '7 1s a face view of one of the stationary armature poles showing the manner of winding the same. Figure 8 is a fragmentary face view of the conductor bar construction for the rotating field; and Figure 9, a diagram of the motor winding.

Referring more particularly to the drawings, the numeral 10 designates an annular frame having op positel -disposed segmental enlargements l1 whic carry the motor windings and the governor mechanism. This frame is adapted to be mounted w1th1n an aperture in the top of the cabinet 12 of the phonograph to support the table, motor and governing mechanism as a complete unit. On its lower face the frame 10 carries a bridge piece 13 which supports a vertically-bored boss 14, the latter forming a bearing-supporting member for the vertical table shaft 15. This shaft is carried by; a self-centering ball thrust bearing 16 at its upper end and is guided at its lower end by a bushing 17 Intermediate its ends the table shaft is secured against longitudinal displacement by a screw 18, the reduced point of which bears within a groove 19 turned in the shaft. 7

. The honograph table 20, which is of the usual 'sc-like form on its upper surface, is mounted on the shaft 15 and carries a plurality of depending lugs 21 which are prefpunching erabl ofQconsiderable weight and cast in- For co-operatlng with the rotating induction field there is provided a stationary segeotangular apertures 24 in a cop-- mental field magnet, the laminated core of a which is designated 26 and is fastened to the lower face of oneof the segmental enlargements ll of the frame. The'laminations of the core 26 are of the form illustrated in Fig. 1, being out to provide relatively long lugs 27 which project radially inwardly and relatively short lugs 28 which project radially outwardly.

By virtue of this peculiar formation of the core 26 I am able to employ advantageously a method of winding which gives superior results. The motor being intended for operation on single phase alternating current and being of the induction type, it would be necessary to provide starting means which would ordinarily take the form of a split-phase winding. I make use of such a splithase winding, but in place of limiting its unction to that of starting, I make it of adequate size and in proper relation to the iron, so that it may be used as a running winding as well, producing a powerful rotating field. In fact, the two windings, i. e., the normal winding and the split-phase winding are in my construction of approximately equal size, strength and efliciency. I

These results are attained by the method of winding illustrated in the drawing. For convenience of description I shall here refer to the prim winding as that one occupying the norm or customary relationshipto the core. These windings designated 29, lodged in slots forming reduced cover portions 28, are arranged to form three poles, as shown in Figure 9, the coils being in tangential planes and occupying the slots be tween the lugs 27 The successive coils are wound in reverse directions,

The split-phase coils designated 30 are wound in radial planes upon those portions of the core 26 between the slots formed by the lugs 27 on the inner peri hery of the core and in the slots between t e lugs 28 on the outer periphery of the core, beingin this manner brought into the closest posslble relationship with the iron.

As shown in the diagram of Figure 9, the split-phase coils 30 are wound to form four poles, i. e., two intermediate poles and two end poles, the intermediate poles designated by the dotted arrows 31 coming between the poles formed by the running windings 29. This is effected by reversin the direction of winding of the consecutive sections of the windings between poles. The windings 29 and 30 are connected in parallel (see Fig. 9) and by their different reactances produce the necessary difference in phase.

By the method of winding described, I obtain, without the use of any auxiliary starting mechanism, a self-starting single phase induction motor having a rotating field and stationary windings, and which is capable of operating efliciently through a wide range of speed.

The lower ends of the lugs 21 carry an annular plate cam 35 which is bent to an approximately sinusoidal curve and is fastened to the lugs by cap screws which confine the cam between vibration-absorbing washers 36 preferably formed of leather fabric or rubber. The sinusoidal plate cam 35 constitutes the governor actuating mechanism. For co-operation therewith 1 provide a governor of the general nature of a balance wheel. The governor mechanism is supported on a depending arm 37 carried by the frame 10 and in turn supporting a horizontal shaft 38. Upon this shaft there is mounted a balance wheel 39, the hub of which has for a bearing a felt bushing 40.

Beyond the balance wheel 89 there is journaled on the shaft 38 a sleeve 41, the outer end of which carries a fork 42 which straddles the edge of the cam plate. The ends of the fork have secured thereto relatively stiff transverse springs 43, the springs carrying at their ends felt contact blocks 44 which bear lightly upon the faces of the plate, as is shown in Figure 5. The fork carrying sleeve 41 is connected with the balance wheel 39 by a spiral spring 45, the inner end of which is secured to the sleeve 41, in the plane of the spring, while the outer end is turned rearwardly to engage a spoke of the balance wheel, being secured thereto by a rivet as shown at 46. The sleeve 41, like the balance wheel 39, has a felt bushing which serves as a bearing. The governor shaft assembly is completed by thrust washers 47 which retain the parts in their proper spaced relationship, these washers also being conveniently made of felt.

For adjusting the period of vibration of the governor balance wheel, there is provided an additional spring in the form of a tension coil 48 caught at one end in the wheel and at the other end secured to a lever 49 ivoted to a lug onthe lower face of the rame. A quick-acting adjustment is provided in the form of a snail cam 50, the cam surface of which acts upon the lever 49, the cam being in turn actuated through a shaft by a thumb wheel 51 on the top of the frame. v

The governor mechanism described operates in the following manner. As the table 20 carrying the sinusoidal cam plate 35 revolves, the-sleeve 41 is oscillated by the contact of the felt blocks 44 with the wavy surfaces. By this oscillation the balance wheel 39 is synchronously oscillated through the spiral 45. If the speed of the table is such as to give an oscillation frequency corresponding to the natural frequency of the balance wheel, as determined by the form and mass of the latter and by the force of the spring, the contact felts 44 follow the curves of the cam plate with very little resistance. If, however, the speed of the table tends toexceed this critical value, the oscillations of the balance wheel will no longer synchronize with the oscillations of the sleeve 41, and, as a result, a considerable pressure will be exerted upon the felt contact blocks 44 causing the latter to act as brakes for retarding the table, thus tending to hold the latter down to a certain definite speed fixed by the periodicity of the balance wheel.

The operation of my improved phonograph motor as a whole is as follows:

The field magnet being provided with the two sets of windings 29 and 30 arranged and connected in the manner shown in Fig. 9, is connected to a single-phase alternating current service line of the proper potential with the result that a torque is exerted upon the rotating field and the table thereby set in motion. This starting torque of the motor described is particularly high and is effective to bring the table up to speed within a relatively short period. In its initial acceleration the table is, of course, out of synchronism with the balance wheel of the governor and the latter, therefore, exerts some retarding effect, but due to the lower veloc ity of the table this retardation is not suflicient to overcome the forward torque of the motor. The latter therefore comes up to the speed determined by the periodicity of the balance wheel, and, in fact, slightly exceeds this speed until the braking effect of the contact blocks 44 balances the surplus torque of the motor. The table is now in normal operation at its governed speed. The designed load, such, for example, as the record and the reproducer needle bearing thereon,

Control of the speed of revolution of the table is obtained by single adjustment, i. e., the thumb-screw 51, which regulates the tension of the spring A8 and thereby varies the natural frequency of the balance wheel. By movement of less than one revolution of this thumb-wheel the speed of the phonograph table may be changed through the widest range required in this service.

This application is a division of my prior application, filed April 5, 1918, which issued as Patent No. 1,329,800 on February 3rd, 1920.

While I have in the foregoing described in considerable detail one specific construction in accordance with my invention, it will be understood that this is illustrative only and for the purpose of making the invention more clear, and that the invention is not to be regarded as limited to any of these details, except in so far as the same are ineluded within the terms of the appended claims in which it is my intention to claim all novelty inherent in my invention as broadly as is permissible in View of the prior art.

I claim: v

1. The combination with a phonograph of a rotating annular induced field member carried by the table shaft thereof, an annular field magnet core concentric with and in operative relation to the induction field memher, said core being provided with radial projections directed toward the induced field member, a series of coils wound in tangential planes about said projections, and a second series of coils of different reactance wound in radial planes between said projections, said series of coils being connected in parallel.

2. A stator for a monophase induction motor comprising a field magnet having a yoke provided with internally extending projections, exciting windings about said pole projections, and reactance windings about said yoke, said reactance windings being in parallel with the exciting windings.

3. A stator for monophase induction motors comprising a field magnet having a yoke provided with internally extending projections, series-connected exciting windings about said pole projections, and series-connected reactance'windings about said yoke, said reactance windings being in parallel with the exciting windings.

4. A stator for a monophase induction motor comprising a field magnet having a yoke provided with internally extending projections, exciting windings about groups of said projections and reactance windings about said yoke and between said projections, said reactance windings being in parallel with said exciting windings.

5. A stator for a monophase induction motor comprising a field magnet having an annular core and internally extending radial projections, alternately-reversed series-connected exciting' windings about successive groups of said projections, and alternatelyreversed series-connected reactance windings about said core and in parallel with said exciting wlndlngs.

HENRY K. SANDELL. 

